John Billingsley isn’t the only one to get a buzz from the countryside; here he reports on some experiences of the so-called ‘hummadruz’.
“This isle is full of noises, sounds and sweet airs” wrote William Shakespeare for Prospero in the play The Tempest. Perhaps he was writing from personal experience, for this isle of Britain certainly has its aural oddities. Among the strangest may well be the hummadruz.
What on (in, under or over) earth is the hummadruz? Orthodox theories cite Low Frequency Noise sensitivity, electro-magnetic pollution or tinnitus, but these conditions do not always seem applicable to a scatter of reports that have occurred over the years, in which people have heard a hum or buzz with no apparent source.
Not much has appeared in earth mysteries publications about this phenomenon; I could only track down a flurry of references in The Ley Hunter in the late 1970s. A letter from the late Sid Birchby in TLH 81 introduced the topic with examples and suggested a working party to investigate it further; he followed this up with additional notes culled from 19th-century newspapers in the Manchester area.
The term hummadruz seems to have been coined in the last century. In 1878 R.E.Bibby, a local musician and composer, recalled from his 1820s childhood a low drone or humming noise heard in suburbs to the south and east of Manchester, especially Gorton, Rusholme and Longsight. It was heard on calm, clear days, usually in the early morning or at dusk.
Even Gilbert White, the naturalist author of The Natural History of Selborne, reported on such a noise in 1769, and gives the impression that it was a common occurrence:
“Humming in the air. There is a natural occurrence to be met with upon the highest part of our downs in hot summer days… a loud humming as of bees in the air, though not one insect is to be seen. The sound is distinctly to be heard the whole common through. Any person would suppose that a large swarm of bees was in motion and playing about his head”. This description very closely matches my own experience of the hummadruz.
In August 1978, I was working with a council conservation team on restoring the footpaths that were to make up the Calderdale Way, near Halifax, West Yorkshire. One hot and sunny afternoon, after a bit of rain in the previous days, we had to clear a mass of holly trees from a trackway, and some of us also set about clearing wood, leaves and silt from a well-trough situated at a bend on the track on the wooded hillside.
While this was going on, I became aware of a buzzing sound, which I first thought to be the hum of woodland flies. Steadily, however, the noise became more intense; I looked around to try and locate the swarm of bees, as I had by then assumed it to be, but could find no centre or direction to the sound. The other two people working on the well were also aware of the sound, but did not find it as loud or bothersome as I did; for me, the sound at its most intense seemed not only to be all around, but inside my head as well. In the end, I went off outside the woodland to trim some holly instead; the sound was still there when we clocked off, but not on subsequent days. The location of this phenomenon was north of Halifax, near Catharine Slack at OS Grid Ref. SE 0910 2831; quite near a road, though not a very busy one, it was not a place one would expect silence nor any quietness beyond our contemporary normal background noise.
Pete Hannah and his wife seem to have had a similar experience in 1972, at Holy Island off the eastern shore of Arran. It was at the site of an old monastery there on a warm and still sunny day that the couple were startled by the sudden onset of a loud buzzing, like a swarm of bees, seeming to come from the ground beneath their feet. They took to their heels and ran, though no insects were to be seen. Years later, reflecting on this experience, he felt that the weather, location and their state of mind – they had just spent a couple of hours musing by the sea and were feeling stilled – had been influential on their perception of the noise, and also that it had seemed to increase in relation to their degree of fear about the proximity of angry bees.
Artist Mazda Munn’s experience is of an “intermittently audible” low frequency hum, “similar to the sound one gets when blowing into the neck of a bottle”, occurring at irregular intervals, varying from 1-40 seconds in duration. She notices it at night or at quiet times during the day in all kinds of weather except windy, at home in rural Ayrshire and on Mull, which suggests it is not an industrially derived sound source. She can find no direction or source, but describes it as more like an electrical than an insect sound.
Mazda Munn has drawn my attention to the Largs Hum, which made the news frequently around 1995; a theory on this noise was low frequency sound emitted by submarines moving in the Clyde Estuary.
Another report comes from Northern UFO News, and brings us more up to date. One summer afternoon in June 1992, Maurice Giffin, an electrical engineer from Barmouth, Gwynedd, was strolling along Llawlech Ridge when he heard a curious buzzing noise. At first, he thought the sound was a swarm of bees, but was unable to find any insects; he did however establish that the sound seemed to come from the earth itself, and could be heard up to 30 m. away. As evening approached, the sound faded away to nothing. A few days later Mr Giffin returned with a low noise amplifier and was able to record the sound.
Later, in 1994, Mr Giffin discovered another two hummadruz zones in the Welsh hills at Cors y Gedol and Cell Fawr. From his studies at all three sites, he has been able to establish that the noise is only audible from mid-May to mid-September on stable, sunny days with a light on-shore breeze. He also notes that all three sites lie close to the 270m. contour and an area of geological faulting. During 1995, Mr Giffin learned of new sites from other witnesses, all in similar locations; the most northerly was at Portmeirion. It is worth noting that at the foot of the Llawlech Ridge is the village of Egryn, famous in the early years of this century for the Egryn Earthlights (see K & S McClure’s Stars & Rumours of Stars).
Reasons & Rumours of Reasons
he tendency would obviously be to ascribe such a sound to insects, but one would expect Gilbert White, at least, to know the difference. Today, we might seek another explanation, like the buzzing one hears in the vicinity of telegraph wires. One 19th-century man thought it might be the sound of the world spinning – in this case, is the hummadruz the true ‘music of the spheres’? Other modernist interpretations might collate the hummadruz with the hum of UFOs. Birchby was inclined to link it with ‘ley energy’, but this implies more about the preconceptions of earth mysteries in the late 1970s (and to some extent still today in non-specialist circles) than anything else.
Canadian research has established recently that sand can ‘sing’, although the precise mechanism is still unknown. Marco Polo, for instance, experienced ‘spirits talking’ in the desert of Lop Nor, and the scientists think that this was probably the effect of sand sheared by the wind. Only certain sand types can do this, and then can have a range of noises from booming to squeaking. Such sands, whatever their base material, have a silica gel layer on the surface of the grain, which causes particles to adhere weakly together, and in that state, movement induces sound. The scientists shook such sands in a bottle to produce a humming noise in their experiments. However, the usual conditions for the hummadruz are still, and as it is wind which creates the sand effect, this would seem not to offer any definite lead.
A seismic origin has been suspected for some noises; Comrie in Perthshire experienced 430 earth tremors over 38 years in the 19th century, many accompanied by sounds like ‘rumbling in the earth’ or ‘a moaning sound in the air’.
There are without doubt aspects of the hummadruz which place it in the broad area of earth mysteries interest. Some reports come from the vicinity of ancient sites or trackways. I heard it at a well on an old packhorse track, for instance, and the Hannahs on a holy island, while Maurice Hewlett in 1913 heard “the expectancy of an air” near Chesilbury Camp near Salisbury – “a very shrill, piercing, continuous music” yet without melody; he followed this up with a vision of ‘oreads’ (hill-spirits) dancing at the same place the next year. Humming and other odd noises are sometimes associated with fairy rings, a wordless humming coming from inside the ring (see Katherine Briggs, The Vanishing People). Mazda Munn is aware of it in a haunted house on an alignment; Kilwinning Abbey is on the same line. She has also heard it in Mull across from Iona Abbey.
In addition to a scatter of 19th-century notes, Birchby found a dozen or so reports from the 1950s through the 1970s. He suggested the following common factors were implied in the reports and needed chasing up:
1. Often heard on hills in summer, but not in cold weather
2. Apparently not insects, aircraft, ear defects, or wind in vegetation
3. Hearers are often musically-gifted with a sensitive ear or otherwise artistic or literary
4. Some reports occur near prehistoric sites or green roads
Ultrasound occurs at frequencies higher than 20 kHz, the normal limit of human hearing; it is produced by bats, dog whistles, dolphins and even the wind as it blows through vegetation or across sand. At the other end of the spectrum is low-frequency infrasound. Either may be produced in certain tectonic movements, and either type of sound may also be involved in the hummadruz experience.
The Dragon Project, which was set up to investigate anomalous effects at ancient sites, was alerted to the possibility of ultrasonic emissions by anecdotes of a bat detector registering at an othcrwise bat-free ancient site, and that skylarks enjoyed Arbor Low stone circle because of ultrasound deriving from there’ ! Experiments were tantalisingly elusive, strong indications of ultrasound at the Rollright Stones and elsewhere occurring only sporadically and generally inconclusively, and not during summer, which conflicts with hummadruz preferences. Both anecdotes and results, howcver, did imply that sunrise is the best time for ultrasonic emission, which was also indicated in the Orgone 93 project.
The point about these frequencies, though, is that they are not generally audible, though the possibility exists that some other factor could bring the sound temporarily into the human range. Yet some kind of association between sound and ancient sites is there, albeit more as part of personal narratives of experience than in hard data. In addition to the experiences mentioned in the first part of this article, ticking and humming have been reported near The Whispering Knights, a dolmen close by Rollright Stones, a hum from a Bronze Age cairn in the Wicklow Mountains of Ireland and a buzz from Arthur’s Stone near Dorstone in Herefordshire .
But what about hearing disorders – is the hummadruz perhaps a result of hearing problems, not an external stimulus? One way to find out might be to cover your ears – if the sound gets quieter, it’s external, but if it gets louder, then it’s internal. In that case it could be tinnitus or even a sound emitted from the vascular system.
Tinnitus, usually thought to be an effect of exposure to over-loud noise, ageing, or stress, generally begins as a high-pitched buzz in the ears, mostly perceived when the environment is quiet and still; it often develops no further than this, but can get to be a persistent and intrusive hum, buzz and/or other noise which intrudes upon everyday life and interferes with concentration and thought processes. It is a real auditory sensation, apparently independent of actual external sound which people can be ‘trained’ to disregard. Tinnitus groups have found that the sounds of nature can be particularly efficacious in curing or reducing the nuisance level of the ailment, by training sufferers to let the noise blend in with background sound, thus reducing its effect on mental processes. A Hull group notes that listening to natural sounds, such as wavelets lapping on a beach, which have been set at a similar volume to the tinnitus somehow pegs the two sound stimuli together. “If you start with the sound about the level of the tinnitus, over the weeks and months you can slowly reduce the sound level and curiously the level of the tinnitus drops with it” explained Bill Howard. Perhaps significantly, though, their main problem has apparently been finding somewhere quiet enough for only natural sounds to be recorded; this suggests severe disruption in the silence/noise ratio even in rural environments. This may itself excite a reflex perception manifesting on the brain as sound.
Some hearing specialists suggest tinnitus may be a ‘survival reflex’ inherited from our hunting days, with the brain latching on to some small and inconsequential sound and insisting that it matters a lot; others describe it as a disfunctional response of the auditory system – even in silence there is a constant flow of impulses arriving at the nerves of the ear and if ‘normal silence’ is not present then the brain can misinterpret the pattern it receives as sound. Some experients like Mazda Munn and myself have noted that while others have been aware of the sound, it has not bothered them; this suggests that the sound is to some extent at least an external, not personal, phenomenon.
The Low Frequency Noise Sufferers’ Association lays the blame for its members’ discomfort at the door of industrial sources, though it has not ruled out “other phenomena that are not yet understood”. Many members feel that the gas grid is the main source of LFN; one pipe in Wales is apparently ‘set off’ by small earth tremors, and similar ‘seismic’ effects may occur from pump or valve operations. Experiments under the direction of Dr David Manley are planned to measure and locate LFN. The noise is known to aggravate stress levels (certain low frequencies, which can rupture human organs, have been used as torture devices; others as crowd control).
All these may have some relation to the hummadruz. Though the sound in the head is small, its incongruity alerts the brain to perceive it more strongly; and although the ‘sound’ may not be externally present as sound, the stimulus on the nerve endings is enough in certain circumstances to disrupt the expected auditory pattern at a certain place and time. Hence, hummadruz hearers are not necessarily hearing a hum or buzz per se, but picking up through their sound sense on some other abnormality in the sensory environment. That could, of course, be some kind of energy (not necessarily unknown or mysterious) normally present in the environment but perceived more strongly under conditions such as those described by Birchby; or to a different ‘quality’ of silence; or even, in modernday hearers at least, it could be a response conditioned by the omission of silence from contemporary pattern of auditory environments – correlating to the 1995 ‘tranquillity survey’ of the Council for the Protection of Rural England, which found a 60% drop since the Second World War in places in England that could be described as tranquil (free from certain classes of noise, such as road and industrial).
In general, the cases cited by Sid Birchby seem to discourage the notion of electro-magnetic pollution in our modern sense at least. A later case he quoted, however, does indeed sound like a Low Frequency Noise ‘attack’; the wife of the author, Edward Hyams, apparently was troubled by a low hum in 1960, and the GPO even removed the telephone and slackened cables in an attempt to counteract it, but GPs – who were generally unaware of this syndrome at the time – could find no medical cause for her condition.
Also likely to be LFN-related would seem to be reports received by The News of the World when they ran a snap survey in 1979. A map showed that odd humming noises were being heard all over Britain, but several were occurring inside houses, which places them in a very different category from the hummadruz; in a number of these, only certain people were aware of the hum (The only natural example appearing in the article “was coming from the direction of the hill at the back of our house” at Rose Hill, Gilsland, in Cumbria). Mazda Munn’s report suggests she may be experiencing something similar to those described in 1979.
Recently I myself have been aware late at night of an intermittent low drone; it seems however to be the fridge next door, somehow amplified through the wall and by the lateness of the night!
It is apparently not simply a contemporary phenomenon, however, though the higher incidence of human auditory problems through noise pollution, LFN and other stimuli is. Gilbert White treats it as normal, but even so the existence of a sourceless sound such as he describes must have inspired some wonder. Was it thought of as some supernatural presence, and if so, could it have any bearing on folk customs such as the whispering sweepers of the Pennines, described evocatively by Bob Pegg: “outside you hear a faint noise, gradually becoming louder, till it sounds as if a swarm of bees is gathering outside in the darkness. Suddenly the door opens and in steps a group of half-a-dozen or so people, their faces blacked to make them unrecognisable the men dressed as women, and the women dressed as men with their jackets pulled inside-out. Each carrries a broom and, ignoring the members of the household, they sweep around the room, and especially the hearth, humming all the while. When they have finished their cleaning job one of them holds out a purse in which you put a few coppers and they leave for their next call without having said a word”. This ‘mumming’, however, was a New Year custom, while the hummadruz, as noted, is especially associated with hot summer days.
Some link to ‘earth lights’ also seems worthy of further investigation, as implied in the Welsh examples and also by one of the reportees in the News of the World, who mentioned that the hum – in Mantilla Road, Tooting, London “seems to be accompanied by a very bright light in the sky, much bigger than a star”. A Lancashire light buzzed, while another disturbingly encountered by a Yorkshire pot-holer hummed as it approached, similar to one in Missouri in 1938 .
But these possible links seem to be as far as we can go – at the moment. The Dragon Project, without consistent and reliable data but plenty of leads, similarly had to leave the matter ‘in the air’. It seems to me that there are at least two kinds of hum being described – one perceived outdoors and sounding like insects, and another tending to occur within buildings and sounding rather I more ‘electrical drone’-like.
Questions are inevitably raised by all this, such as: Are there any reports from other countries? Is it a human auditory response to certain atmospheric conditions? Is there any connection between the hummadruz and the experience of numinous atmospheres at certain places? It is, however, the kind of experience that is quite likely to go unreported as a temporary and minor personal auditory aberration or even, in these days of acute noise pollution and, as the CPRE reports, widespread loss of ‘tranquil places’ across Britain, to exist unperceived by our less sensitive ears. Yet earth mysteries and its fellow travellers are always ready to come up with new hypotheses and experiments, and perhaps some reader may have new experiences or suggestions that might bring us closer to identifying the curious hummadruz.
The hummadruz, moreover, is just one of several ways in which sound may be connected with ancient sites and/or numinous places, and this is an area which is receiving increasing attention in the field at present. We are always glad to hear of sound experiences in the landscape.
 Devereux, Paul. Places of Power. Blandford 1990, p.52
 Collins, Andy. Alien Energy. ABC 1994, p.l26-9.
 Devereux 1990, p.73 1734.
 Devereux, Paul. Earth Lights Revelation. Blandford 1993, p. 100,106,128
S.L.Birchby, letter, The Ley Hunter 81, p.18 (1978); S.L.Birchby, ‘The Hummadruz’, TLH 84 (1979); Frank Earp, letter, TLH 86, p.12 (1979); Peter Hannah, letter, TLH 88, p.34 (1980). News of the World, 25-2-1979, p.7; Northern UFO News 173, March 1996; Hull Tinnitus Group, Yorks Post 28-12-96; Bob Pegg, Rites & Riots, Blandford 1981 p.73; The Guardian, 8-3-97, p.10; Mazda Munn, letter, Fortean Times 95, p.52 & pers. comm.; Julia Smith, pers. comm.; Stuart Gray-Thompson, pers. comm.
Published in two parts: NE70 (Summer 1997) pp.11-13, and NE71 (Autumn 1997), pp.12-16
Further reports on the hummadruz
My two-part article on the hummadruz in NE 70 & 71 excited greater reader feedback than we have ever had before in the long history of the magazine. If is quite apparent that we stirred up a hornets’ nest of experiences, and that the hummadruz is one of those damned things whose time may have come round at last!
Though it is not a common experience, our response shows that we have moved from a smattering of isolated reports to an experience that, as Gilbert White noted two hundred years ago, should be accepted as one of the natural – if mysterious – phenomena of the environment.
Several people continue to ask me what I think the hummadruz is, though I have no more idea than they do! I do tend, however, to feel the ‘true’ hummadruz is heard outdoors, and that indoor hums and buzzes are likely to be related to electronic pollution and electro-sensitivity.
My thanks go out to all the people who have sent in their reports, and I hope that some day these and others like them will lead to some further understanding of the hummadruz. In the meantime, channels are still open, and I would be glad to hear of other experiences of and suggestions about this curious sound.
The following is just a selection of the reports we have received; unfortunately, we have had to heavily edit these for space reasons, for which we apologise to our correspondents.
Anne Hewland, Brighouse:
The hummadruz article (NE 70) was fascinating as my husband and two sons experienced something similar this year
March 29th 1997 at St Non’s Well, near St David’s, Pembrokeshire. I was there too and couldn’t hear a thing. My husband thought it was bees and there were some bees in the gorse, which I could hear; he said he could hear those bees too but that the other buzzing was louder. Of the conditions mentioned – it was a calm and sunny day, we were on hills sloping down to the sea and were of course at an ancient site [the nearby chapel stands within a ring of stones – eds].
In response to your article on the hummadruz, here are some experiences I recall from the Yorkshire Dales:
Malham: While sitting beside Janet’s Foss; I had been swimming in the pool at the foot of this small tufa waterfall and was lingering while dressing. I heard what I thought was the sound of a swarm of bees in the distance. In those days, being asthmatic, I was very frightened of being stung by bees or wasps; I sped up the path to the road and no longer heard the sound.
Gordale Scar: The dry valley above which I used to get to Malham Tarn. Sitting down one day eating sandwiches I heard the hum again, but this time as I was in wide-open upland I did not run away. I sat and finished my meal, thinking about the pleasure of the hum and fell asleep. On waking I was aware the sound was no longer there and I felt I had forgotten something special that I had encountered in my sleep.
Ingleton: Near the Ingleton village end of the Waterfall Walk, I was lying back on a bank on a warm summer day. The noise slowly impinged on my mind and ears. I was not afraid, but happy to hear it. As I lay I meditated on nature’s gifts and was at ease.Suddenly I shot upright because the sound was very intense; I walked to the stream and started skimming pebbles. At the water’s edge the sound died away. After what seemed a considerable time it was no longer there.
Andy & Carol Norfolk, Cornwall:
I heard the hummadruz yesterday (6-7-97). The Cornish EMG went for one of our summer walks to Zennor Quoit and Trebdrine Hill on the north coast to the W of St Ives. It was a glorious sunny day with a cloudless sky and no wind. We walked up to the Quoit from near Eagles Nest. It is close to the 222m contour. When we got to the quoit it was quiet; I didn’t notice any noise except a lot of chatter. Most of us then walked to Sperris Quoit and then on to the top of Trendrine Hill where there is a trig point at 247m ASL. Carol, who stayed on her own at Zennor Quoit, heard a loud humming/buzzing noise as if there were large numbers of bees or other insects flying around. Of course there were hardly any to be seen. Carol and I have kept bees in the past and the noise was very like a contented hive, but there were no bees nearby. The noise was all around and it was impossible to locate a source.
Luckily, having carefully read the last NE I was able to impress Dionne and Carol by being able to give the noise a name!
The article ‘Sites & Sounds’ (NE 70) was of some interest to me, as audio readings in the topsoil have been recorded at many areas, from Duncansby Head to near Penzance to County Wicklow, during the last eighteen years.
Many frequencies within the range 100Hz to 10000Hz were registered. Sine waves from 500Hz to 3.60KHz were normally detected. These frequently inter-modulated; this seemed to disturb the few who heard the sounds. However, the phenomenon is not universal and has to be searched for.
Nick & Carol Ford, Southampton:
The one and only time we have experienced ‘hummadruz’ was in Northern France in June 1990. A piece of the infamous Somme battlefield, between the villages of Beaumont and Hamel, has been preserved in its original state as a memorial. Like all such places, it’s noticeably quieter than similar countryside nearby which hasn’t been fought over.
On a hot afternoon we began to walk across No Man’s Land from the Allied trenches to the German, a distance of only about 400 metres. One of us soon began to experience a feeling approaching panic, which can only be described as a fear of falling into the ground. After a few steps, we became aware that the ground- beneath our feet was alive and buzzing audibly. Our first thought was that there were many underground bees’ or wasps’ nests – but we couldn’t see any insects above ground. The buzzing grew so intense as we walked to wards the middle that we got a gruesome mental picture of millions of flies swarming over rotting bodies…
Andrew Green, Sussex:
Re hummadruz: having heard similar sounds under similar circumstances to the ‘witnesses’ might I suggest the cause of the noise (which I found to be the case in the three incidents I experienced) is either a bumble bee nest or a large nest of flying ants?
Adrienne & David, Bury:
Adrienne told JB on the phone of hearing the hummadruz on 16-8-97 in Grinlow Wood, on the hillside between Poole’s Cavern and Solomon’s Temple (both ancient sites) in Buxton, Derbyshire. True to form, the weather was ‘sweltering’ and still, and they thought it was bees swarming close to the ground, though none were to be seen!
Don’t forget to look at the back issues because there are a host of other articles from the catalogue of work to give you an even greater taste of what Northern Earth has to offer.
Published in NE72 (Winter 1997), pp.20-21
Abuzz about zoological hums
Paul Screeton identifies some possible scape-giraffing in the hunt for low-frequency noise culprits
Northern Earth seems to have become the home of hummadruz speculation and a forum for fortean debate and reporting some dubious explanationism.
The editor has asked me to stick my neck out and pen a few notes on giraffes becoming prime suspects on two fronts. For biologists now say they have discovered that giraffes hum. People had earlier speculated that giraffes are unable to produce any substantial sounds because it is physically difficult for them to generate sufficient airflow through their long necks to produce vocalisations.
After reviewing almost 1000 hours of sound recordings in three European zoos, Angela Stöger, at the University of Vienna, Austria, picked up a weird humming coming from the giraffe enclosures in all three zoos at night. “I was fascinated, because these signals have a very interesting sound and have a complex acoustic structure”, she says.
The ‘hum’ turned out to be a low frequency sound, of about 92 hertz. That’s not infrasound – we can still just about hear it unaided. Stöger and her colleagues say the hum varies in duration and contains a rich combination of notes. (New Scientist, 17-9-15)
Subsequently, a group of neighbours who live near Paignton Zoo in Devon claimed a humming noise from a giraffe enclosure was making them ill and a petition complaining about a low-frequency noise attracted 165 signatures from frustrated residents who say an independent investigation should be carried out.
They report unwelcome side effects from the noise – described by one as “like a distant engine or washing machine” – including headaches, tremors, a feeling of irritation, sickness and disturbed sleep. Neighbours claim the noise is coming from the building where giraffes live. The droning sound is said to resemble “a persistent low-level ‘hum’ or ‘thrumming’.
A Daily Telegraph article acknowledges Stoger’s research, but Paignton Zoo denied the animals were the reason for this complaint. Local resident, Peter Thorne, said the problem may come from the heating system in the zoo’s Giraffe House. Another neighbour, Gillian Watling, claimed to have suffered tremors. She said she had night-time symptoms including “waves passing down the muscles in my back, buttocks, thighs and calves. I have also suffered heart palpitations like the feeling you get standing next to a large bass speaker that is playing music very loudly at a rock concert”.
A Torbay Council spokesperson said: “We have conducted multiple assessments in several locations, including a factory and Paignton Zoo’s Giraffe House, to try to identify where reported low-frequency noise is coming from. However, our officers have been unable to hear or detect any low-frequency noise that would be an issue. Paignton Zoo declined to comment, saying that the issue was in the hands of lawyers. (Daily Telegraph, 23-2-16)
Another news item claimed: “Some researchers believe that micro-seismic activity from long ocean waves impacting on the seabed causes underlying rocks to vibrate and produce the droning sound, which can be conducted great distances inshore under certain geological conditions. Equally, the hum could be coming from a faulty air conditioning unit. Or just giraffes that don’t know the words to a song”. (Daily Mirror, 23-2-16)
Published in NE151 (December 2017), p.25